from __future__ import print_function
import os
from numpy.random import RandomState

from ase.build import molecule
from ase.vibrations import Vibrations
from ase.vibrations import Infrared


class RandomCalculator():
    """Fake Calculator class.

    """
    def __init__(self):
        self.rng = RandomState(42)

    def get_forces(self, atoms):
        return self.rng.rand(len(atoms), 3)

    def get_dipole_moment(self, atoms):
        return self.rng.rand(3)


atoms = molecule('C2H6')
ir = Infrared(atoms)
ir.calc = RandomCalculator()
ir.run()
freqs = ir.get_frequencies()
ints = ir.intensities
assert ir.combine() == 49

ir = Infrared(atoms)
assert (freqs == ir.get_frequencies()).all()
assert (ints == ir.intensities).all()

vib = Vibrations(atoms, name='ir')
assert (freqs == vib.get_frequencies()).all()

# Read the data from other working directory
dirname = os.path.basename(os.getcwd())
os.chdir('..')  # Change working directory
ir = Infrared(atoms, name=os.path.join(dirname, 'ir'))
assert (freqs == ir.get_frequencies()).all()
os.chdir(dirname)

ir = Infrared(atoms)
assert ir.split() == 1
assert (freqs == ir.get_frequencies()).all()
assert (ints == ir.intensities).all()

vib = Vibrations(atoms, name='ir')
assert (freqs == vib.get_frequencies()).all()

assert ir.clean() == 49
